1. Field of the Invention
The circuit is a type of phase-locked loop, i.e. a narrow-band filter which produces an output signal following the strongest signal frequency in the designed circuit signal bandwidth. They are widely used to produce the clock signal in the read-back date in magnetic disc and tape memories. This circuit can also perform as a frequency multiplier and divider by proper selection of components.
2. Description of the Prior Art
The closest art of which applicant is aware is U.S. Pat. No. 3,878,474 (Runge). Runge employs a voltage-controlled oscillator rather than the flywheel rank circuit of the instant invention. This difference creates a significant difference in capability and response. Other prior art akin to the invention comprises U.S. Pat. Nos. 3,204,195 (Maestre), 3,130,375 (Rotier et al.), 3,506,968 (Preti) and 3,908,174 (Hamada). This group of patents all disclose variations on the common RC oscillator aimed at preventing output phase shift.